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Comment by tachyonbeam | Hacker News Reader

I would think that some protection is better than none, but besides that, the wind is probably very uncomfortable at that speed.

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The truck in front is blocking the wind though, which is the point. Assuming she was going all out to fight the leftover wind, it probably felt like 40mph.

I wonder what sort of ridiculous speeds could be attained by a cyclist in a [long] vacuum chamber.

I suppose the athlete would need to wear an EVA suit (or a diving suit? the requirements are sort of between the two), so that'd be a bit of a damper on their peak performance, but still.

There's a comment here that references a record set on a treadmill: https://news.ycombinator.com/item?id=18020912 ...over 200MPH.

Of course, that sounds more like a skill involving reduction of friction and outputting as much power through the legs as possible than the more difficult act of also controlling a bike at those speeds.

You can forget the electro-magnetic cars Elon, just give me the vacuum tube and I'll jump on my bike. If I could sustain anything close to that in a vacuum tube I would probably ride rather than taking some cross country flights.

Why bike alone? Imagine 10+ people on one sled, each with their own powertrain. Now people can take turns resting as well.

I'm a well above average cyclist, unless there's some efficiency from group cycling then reversion to the mean doesn't help me.

The treadmill record that Wikipedia mentions is probably comparable to what the vacuum chamber record would be, because there's no forward-to-back air resistance, only mechanical and rolling resistance, and a trivial amount of air resistance associated with the cyclist's leg movements.

https://en.wikipedia.org/wiki/Bruce_Bursford

I wonder if there's a non-trivial amount of air resistance due to the wheel spokes whirling around at whatever RPM is necessary to attain 200mph? In the real world, it's negligible, but at that high RPM it seems like it must account for something.

likely done on disc wheels so no spokes

Yes, as the sibling says they'd be using disc wheels. I'm a bit surprised that for the OP's speed record they weren't - maybe they were more worried about crosswind wrecking the effort, versus absolute efficiency.

With rollers (what I'd think the "treadmill" discussed above actually is), and a normal road bicycle, you can feel, or at least hear, the resistance just from the spokes in a spoked wheel when you really get get them spinning "real world" fast.

On fancier road race wheels, the spokes are "bladed" for this reason - their cross section is flattened to minimise aerodynamic drag. Remember that when you're riding a bike in normal conditions, the top of the wheel is hitting the oncoming air at up to twice the speed of the bike. Though, there's also a substantial amount of appearance/marketing/armchair-engineering around...

> I wonder if there's a non-trivial amount of air resistance due to the wheel spokes

Even amateur cyclists often use "aero wheels" that no longer have spokes. They make a difference in the wind or at 20mph.

Regular diving suits operate at ambient pressure so they're useless in a vacuum: you wouldn't be able to breathe and would lose consciousness in seconds. Pressure suits like what astronauts and high-altitude pilots wear are so bulky and stiff that cycling would be nearly impossible.

Maybe a wind tunnel, with the wind in the same direction as the direction of travel.

I don't think this is feasible with today's wind tunnels, though.

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